TY - JOUR AU - Zhang, Zhong-Wei AU - Wu, Zi-Li AU - Feng, Ling-Yang AU - Dong, Li-Hua AU - Song, An-Jun AU - Yuan, Ming AU - Chen, Yang-Er AU - Zeng, Jian AU - Chen, Guang-Deng AU - Yuan, Shu PY - 2016 M3 - Original Research TI - Mg-Protoporphyrin IX Signals Enhance Plant’s Tolerance to Cold Stress JO - Frontiers in Plant Science UR - https://www.frontiersin.org/articles/10.3389/fpls.2016.01545 VL - 7 SN - 1664-462X N2 - The relationship between Mg-protoporphyrin IX (Mg-Proto IX) signals and plant’s tolerance to cold stress is investigated. Arabidopsis seedlings grown for 3 weeks were pretreated with 2 mM glutamate (Glu) and 2 mM MgCl2 for 48 h at room temperature to induce Mg-Proto IX accumulation. Then cold stress was performed at 4°C for additional 72 h. Glu + MgCl2 pre-treatments alleviated the subsequent cold stress significantly by rising the leaf temperature through inducing Mg-Proto IX signals. The protective role of Glu + MgCl2 treatment was greatly compromised in the mutants of Mg-Proto IX synthesis, Mg-Proto IX signaling, and cyanide-resistant respiration. And the enhancement of cold-responsive gene expression was greatly compromised in the mutants of Mg-Proto IX synthesis, Mg-Proto IX signaling and ABA signaling, but not in the mutant of cyanide-resistant respiration. Cold stress promoted cyanide-resistant respiration and leaf total respiration exponentially, which could be further induced by the Glu + MgCl2 treatment. Mg-Proto IX signals also activate antioxidant enzymes and increase non-enzymatic antioxidants [glutathione but not ascorbic acid (AsA)] to maintain redox equilibrium during the cold stress. ER -